The present invention relates to gaseous fuel engines with fuel injectors for introducing gaseous fuel (i.e., fuel that naturally exists in a gaseous state, rather than a liquid state) into intake ports of an internal combustion engine, for example in a passenger vehicle. Gaseous fuels include natural gas (primarily methane) and derivatives thereof, such as butane and propane, but do not include gasoline. Natural gas can be used to power internal combustion engines. Compared to conventional engines, vehicles run on natural gas are environmentally friendly while outputting less engine noise than traditional diesel-powered engines.